Photography is the art of capturing light, originally on light-sensitive paper, and today more commonly by means of digital sensors. Optimal use of lighting can make a difference between a good shot and a great one. The importance of lighting in image capture can be observed from the multitude of heavy lighting equipment that is normally present in any professional photographic studio, theater, movie or TV set.
In motion pictures, lighting may be used not only to help actors and sets look their best, but as an integral part of storytelling to set mood, direct attention, and underscore performance. The importance of lighting may be reflected in the high proportion of time and expense spent on lighting: by some estimates, one half or more of the valuable time spent on a set may be involved in setting up the lighting. Moreover, the fact that in large part, the lighting may have to be finalized at the time each scene is filmed and has limited scope for modification in post production phase, adds complication and cost to principal photography. Also, detecting the interplay of lights and shadows on an object provides meaningful information concerning the shape and/or surface characteristics of an object under study.